The present invention relates to the field of telephone conference call management, and in particular to distributing conference call processing tasks among different traffic nodes.
Conference calling is an increasingly important business and social tool. The decreasing cost of telephone connections and of conference services has led to a still further increase in demand. In addition, the number of desired participants is increasing as well. Conference calls with hundreds of participants are not uncommon.
With current conference call systems, the microphone audio from each participant is sent to a shared conference call server. The conference call server combines the microphone audio from all of the calls and sends it back to each participant for playback. Each additional participant increases the required communications traffic bandwidth of the conference call server. As telephone conference call processing moves to video conference call processing, the bandwidth demands are increased still further.
In certain large party conference call systems, the conference call server evaluates the signal of each active audio signal that it receives. It then selects a few of the audio signals to combine for the playback audio. For a conference call with 200 participants, there may be only 20 participants speaking at the same time. Of those, the conference call server selects the 3 to 10 with the highest energy level and limits the playback audio to those audio signals. Any more than 3 to 10 simultaneous speakers can render the playback audio unintelligible. Before sending the audio back to a subscriber, the conference server may also subtract the audio that came from that subscriber. This reduces feedback and unpleasant echo delays. The conference call server may do this for each of the 20 or so subscribers that have active audio. All of this measuring and combining and subtracting places high demands on the processing power of the conference call server. The demands increase significantly as the number of participants and active participants increases. The demands increase still further to support video conferencing.